diff --git a/src/test/preflight.test.js b/src/test/preflight.test.js
index 4f6e4c6..359f4e7 100644
--- a/src/test/preflight.test.js
+++ b/src/test/preflight.test.js
@@ -4,7 +4,7 @@ import axios from 'axios';
 import { mkdtemp, writeFile, chmod, rm } from 'fs/promises';
 import { tmpdir } from 'os';
 import { join } from 'path';
-import { checkRequiredEnv, verifyGiteaToken, verifyCommentToken, verifyLLM, runPreflight } from '../preflight.js';
+import { checkRequiredEnv, verifyGiteaToken, verifyCommentToken, verifyLLM, fetchCodexModels, runPreflight } from '../preflight.js';
 
 const LLM_ENV_KEYS = [
   'AI_ASSISTANT_CLI', 'MODEL', 'OPENCODE_MODEL', 'PATH',
@@ -130,18 +130,52 @@ describe('verifyLLM', () => {
     assert.match(result.error, /AI 助理 CLI/);
   });
 
-  it('passes when a supported assistant CLI is detected', async () => {
+  it('passes when a supported assistant CLI is detected and the model is in the codex list', async () => {
     clearLLMEnv();
     await installFakeCLI('codex');
     process.env.AI_ASSISTANT_CLI = 'codex';
-    process.env.MODEL = 'gpt-5-mini';
+    process.env.MODEL = 'gpt-5.4-mini';
 
-    const result = await verifyLLM();
+    const result = await verifyLLM({
+      fetchCodexModelsFn: async () => ({ ok: true, slugs: ['gpt-5.5', 'gpt-5.4-mini'] }),
+    });
 
     assert.equal(result.ok, true);
     assert.equal(result.provider, 'codex');
     assert.equal(result.command, 'codex');
-    assert.equal(result.model, 'gpt-5-mini');
+    assert.equal(result.model, 'gpt-5.4-mini');
+    assert.deepEqual(result.models, ['gpt-5.5', 'gpt-5.4-mini']);
+  });
+
+  it('fails when codex auth is invalid (model list check reports 401)', async () => {
+    clearLLMEnv();
+    await installFakeCLI('codex');
+    process.env.AI_ASSISTANT_CLI = 'codex';
+    process.env.MODEL = 'gpt-5.4-mini';
+
+    const result = await verifyLLM({
+      fetchCodexModelsFn: async () => ({ ok: false, error: 'codex 認證失效（HTTP 401）——token 已被撤銷或過期，請重新登入 codex 並更新 LLM_OAUTH secret' }),
+    });
+
+    assert.equal(result.ok, false);
+    assert.equal(result.provider, 'codex');
+    assert.match(result.error, /HTTP 401/);
+    assert.match(result.error, /LLM_OAUTH/);
+  });
+
+  it('fails when the configured model is not in the codex available list', async () => {
+    clearLLMEnv();
+    await installFakeCLI('codex');
+    process.env.AI_ASSISTANT_CLI = 'codex';
+    process.env.MODEL = 'gpt-9-imaginary';
+
+    const result = await verifyLLM({
+      fetchCodexModelsFn: async () => ({ ok: true, slugs: ['gpt-5.5', 'gpt-5.4-mini'] }),
+    });
+
+    assert.equal(result.ok, false);
+    assert.match(result.error, /不在 codex 可用清單/);
+    assert.match(result.error, /gpt-5\.4-mini/);
   });
 
   it('fails when a requested CLI is not installed', async () => {
@@ -157,6 +191,59 @@ describe('verifyLLM', () => {
 
 });
 
+describe('fetchCodexModels', () => {
+  async function writeAuth(json) {
+    tempDir = await mkdtemp(join(tmpdir(), 'codex-auth-test-'));
+    const authPath = join(tempDir, 'auth.json');
+    await writeFile(authPath, JSON.stringify(json));
+    return authPath;
+  }
+
+  it('returns the model slugs on HTTP 200', async () => {
+    const authPath = await writeAuth({ tokens: { access_token: 'tok', account_id: 'acc' } });
+    let capturedUrl, capturedHeaders;
+    const result = await fetchCodexModels({
+      authPath,
+      fetchImpl: async (url, opts) => {
+        capturedUrl = url;
+        capturedHeaders = opts.headers;
+        return { status: 200, ok: true, json: async () => ({ models: [{ slug: 'gpt-5.5' }, { slug: 'gpt-5.4-mini' }] }) };
+      },
+    });
+    assert.deepEqual(result, { ok: true, slugs: ['gpt-5.5', 'gpt-5.4-mini'] });
+    assert.match(capturedUrl, /client_version=/);
+    assert.equal(capturedHeaders['Authorization'], 'Bearer tok');
+    assert.equal(capturedHeaders['chatgpt-account-id'], 'acc');
+  });
+
+  it('reports an auth failure on HTTP 401', async () => {
+    const authPath = await writeAuth({ tokens: { access_token: 'revoked' } });
+    const result = await fetchCodexModels({
+      authPath,
+      fetchImpl: async () => ({ status: 401, ok: false, json: async () => ({}) }),
+    });
+    assert.equal(result.ok, false);
+    assert.match(result.error, /HTTP 401/);
+    assert.match(result.error, /LLM_OAUTH/);
+  });
+
+  it('fails when the auth file cannot be read', async () => {
+    const result = await fetchCodexModels({
+      authPath: join(tmpdir(), 'definitely-missing-codex-auth-xyz.json'),
+      fetchImpl: async () => ({ status: 200, ok: true, json: async () => ({ models: [] }) }),
+    });
+    assert.equal(result.ok, false);
+    assert.match(result.error, /無法讀取 codex 認證檔/);
+  });
+
+  it('fails when the auth file lacks an access_token', async () => {
+    const authPath = await writeAuth({ tokens: {} });
+    const result = await fetchCodexModels({ authPath, fetchImpl: async () => ({ status: 200, ok: true, json: async () => ({}) }) });
+    assert.equal(result.ok, false);
+    assert.match(result.error, /缺少 tokens\.access_token/);
+  });
+});
+
 describe('runPreflight', () => {
   function makeDeps(overrides = {}) {
     return {